Due to an increase in cost and the associated decline in capacity of landfills, disposal of solid, hazardous, radioactive mixed, and low level radioactive wastes mandates efficient utilization of wastes. The disposal would be less costly if landfills were not part of the storage facilities. The capacity crisis has become a significant concern around the country, particularly in the Northeast where landfill sites are small in size and in numbers. According to EPA data (1986), for example, more than half of the existing landfills will reach their capacity within eight years. About 40% of the landfills involve less than ten acres and nearly 95% are smaller than 100 acres. Accordingly, about one third of all landfills receive less than 30 tons per day of waste and only 5% receive more than 500 tons. Privately owned cites represent approximately half of the country's remaining disposal capacity.
There are several methods of disposing of hazardous waste. Landfills have been used as bedding grounds but uncontrollable contamination problems have led communities to restrict landfills especially in highly populated areas. When toxic wastes are disposed of on land, contaminated liquid may drain and leak from the waste sites and pollute ground water. Likewise, land application techniques and deep well injection have the same drawbacks as landfills. Government regulations now require industry to find alternative technologies to replace landfilling as a method of disposing of hazardous wastes.
Incineration is an old method of disposing of waste. Unfortunately, volatile wastes eliminated this method of disposal as a consideration of disposing of hazardous wastes material. One problem with the incineration of industrial wastes arises from the necessity of a supplying a blended feed to the incinerator and to avoid large fluctuations in the burning characteristics of the waste. The requirement for blending implies that there be a fairly extensive, and segregated, storage system for the various types of waste. This storage facility must take into account the widely varying physical and chemical natures of the waste: in flammability, toxicity, corrosiveness, handleability and mutual compatibility with other wastes. The storage site of the operation, together with the laboratories and staff required for supervision and control purposes, can become complex and expensive. It is apparent that a well designed and managed incinerator facility for industrial waste can become expensive to build and operate. The problem of obtaining the necessary permits from federal and local regulatory agencies is formidable.
Finally, solidification techniques now offer the safest method of disposing of hazardous waste material. Encapsulation can be divided into two subdivisions: micro and macro. Microencapsulation attempts to seal each waste within a solid matrix while macroencapsulation is the process by which the matrix containing the waste is encapsulated. The costs of preparing a solid matrix are incredible in disposing of large amounts of hazardous waste material. Prior art methods of disposing of hazardous waste in sealed metal containers fail because of corrosion problems.